CVE-2025-37756
net: tls: explicitly disallow disconnect
In the Linux kernel, the following vulnerability has been resolved:net: tls: explicitly disallow disconnectsyzbot discovered that it can disconnect a TLS socket and thenrun into all sort of unexpected corner cases. I have a vaguerecollection of Eric pointing this out to us a long time ago.Supporting disconnect is really hard, for one thing if offloadis enabled we'd need to wait for all packets to be _acked_.Disconnect is not commonly used, disallow it.The immediate problem syzbot run into is the warning in the strp,but that's just the easiest bug to trigger: WARNING: CPU: 0 PID: 5834 at net/tls/tls_strp.c:486 tls_strp_msg_load+0x72e/0xa80 net/tls/tls_strp.c:486 RIP: 0010:tls_strp_msg_load+0x72e/0xa80 net/tls/tls_strp.c:486 Call Trace: <TASK> tls_rx_rec_wait+0x280/0xa60 net/tls/tls_sw.c:1363 tls_sw_recvmsg+0x85c/0x1c30 net/tls/tls_sw.c:2043 inet6_recvmsg+0x2c9/0x730 net/ipv6/af_inet6.c:678 sock_recvmsg_nosec net/socket.c:1023 [inline] sock_recvmsg+0x109/0x280 net/socket.c:1045 __sys_recvfrom+0x202/0x380 net/socket.c:2237
- Affected
- Linux
- CVSS v3.1 NVD
- 5.5 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H - CVSS v3.1 CNA
- 7.8 HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - EPSS
- 0.30% chance of exploitation in the next 30 days, 21st percentile
- Published
- 2025-05-01
- Updated
- 2026-10-15
Exploit collections (1)
- linux/kernelctf/CVE-2025-37756_mitigationgoogle/security-research
Security advisories
- https://git.kernel.org/stable/c/2bcad8fefcecdd5f005d8c550b25d703c063c34a
- https://git.kernel.org/stable/c/5071a1e606b30c0c11278d3c6620cd6a24724cf6
- https://git.kernel.org/stable/c/7bdcf5bc35ae59fc4a0fa23276e84b4d1534a3cf
- https://git.kernel.org/stable/c/8513411ec321942bd3cfed53d5bb700665c67d86
- https://git.kernel.org/stable/c/9fcbca0f801580cbb583e9cb274e2c7fbe766ca6
- https://git.kernel.org/stable/c/ac91c6125468be720eafde9c973994cb45b61d44
- https://git.kernel.org/stable/c/c665bef891e8972e1d3ce5bbc0d42a373346a2c3
- https://git.kernel.org/stable/c/f3ce4d3f874ab7919edca364c147ac735f9f1d04